Beat-Relevant Signals in Auditory Cortical Responses to Musical Excerpts

Musical beat perception is widely regarded as a high-level ability involving widespread coordination across brain areas, but how low-level auditory processing must necessarily shape these dynamics, and therefore perception, remains unexplored. Previous cross-species work suggested that beat perception in simple rhythmic noise bursts is shaped by neural transients in the ascending sensory pathway. Here, we found that low-level processes even substantially explain the emergence of beat in real music. Firing rates in the rat auditory cortex in response to twenty musical excerpts were on average higher on the beat than off the beat tapped by human listeners. This "neural emphasis" distinguished the perceived beat from alternative interpretations, was predictive of the degree of consensus across listeners, and was accounted for by a spectrotemporal receptive field model. These findings indicate that low-level auditory processing may have a stronger influence on the location and clarity of the beat in music than previously thought.